The nonlinear seismic response of tall shear wall structures

Abstract

New building codes are tending to place considerable value on the use of deterministic dynamic analyses as a means of assessing the ability of engineering structures to withstand severe seismic ground motions. An investigation of the more important factors affecting such an analysis, derived specifically for tall ductile shear walls, was undertaken. Initial considerations included the selection, and the derivation where necessary, of suitable structural idealisations, material constitutive relationships and numerical integration schemes, leading to an analysis which was sufficiently representative and economically viable. The basic problem of program verification followed. Difficulties in ensuring that reliable accurate results were being obtained arose when certain types of structural idealisation and integration procedures were used. When these problems, which initially handicapped confident application of the program, had been satisfactorily resolved a sensitivity study of a realistic structure was performed. Results presented illustrate important characteristics of structural behaviour and the capabilities of the implemented analysis. Because it is vital that theoretical idealisations of reinforced concrete components should be based on experimental evidence, the case of slab coupling of shear walls was investigated with a sequence of reinforced concrete models. Interest was first concentrated on aspects of slab design, especially the control of punching shear within the range of deformations likely to occur in a seismic disturbance. Limited attempts were made to match standard idealised hysteretic relationships to the experimental responses to allow an improved dynamic analysis of structures incorporating these components. Finally, a pilot test of a slab coupling unit with a monolithically cast shallow beam was performed